Shear Bond Strength Evaluation of Different Composites Used As Lingual Retainer Adhesives

The aim of this study was to determine the shear bond strength (SBS) levels and fracture modes of different composites used as lingual retainer adhesives. Sixty human mandibular incisors were used, that mounted in acrylic resin leaving the buccal surface of the crowns parallel to the base of the moulds. Randomly three groups were constructed, each containing 20 teeth. Transbond-LR (3M-Uni-tek), Transbond-XT (3M-Unitek) and Venus Flow (Heraeus Kulzer) were tested. Materials were applied to the teeth surface by packing the material into the cylindrical plastic matrices with a 2.34 mm internal diameter and a 3 mm height (Ultradent) to simulate the lingual retainer bonding. For SBS testing, the specimens were mounted in a universal testing machine, and an apparatus (Ultradent) attached to a compression load cell was applied to each of the specimen until the failure occurred. The SBS data were analyzed using analysis of variance and Tukey tests, and chi-square test was used to analyze the fracture modes. The statistical tests indicated that Transbond-LR shows statistically significant higher SBS (24.7±9.25 MPa) then Transbond-XT (12.01±4.98 MPa) and Venus Flow (14.07±5.25 MPa) (P<0.001) whereas the difference between Transbond-XT and Venus Flow was not significant. In general, a greater percentage of the fractures were adhesive at the tooth-composite interface (60%% for Transbond-LR and Venus Flow and 90°% for Transbond-XT) and no statistically significant difference was found between the groups. According to the results of this study, Transbond LR was found to be most appropriate material for the tested specification

An Evaluation on Signature Knowledge and Awareness of Turkish Teacher Candidates

Signature is developed by individuals different from other biological traces such as DNA and fingerprint. The development of signing ability that takes place in the main heading of writing education, is under the responsibility of individuals, peers of individuals and teachers of individuals. The aim of this study is to evaluate the knowledge and awareness levels of the students in Turkish Teaching Department regarding the concept of literature. In this study in which the questionnaire model has been implemented, qualitative and quantitative data have been collected by means of Signature Knowledge and Awareness Form that was composed by the researchers. 298 students studying in Turkish teaching department participated in this study. The main results of the study are as follows: 65,4% of the teacher candidates who participated in the study did not receive information about signature in education level. 17,4% of the teacher candidates stated that their teachers guided them about signature formation process. Furthremore, 28,9% of the participants stated that they forged a signature in a period of their lives. It has been identified in the study that the most frequently used key words of the participants are the concepts such as approval, personal symbol, authenticity, representation and personal mark

DOKUZ EYLÜL ÜNİVERSİTESİ HASTANESİ HEMŞİRELERİNİN KAN VE BEDEN SIVILARINA YÖNELİK ÖNLEMLER KONUSUNDA BİLGİ DÜZEYLERİ

SAĞLIK ÇALIŞANLARI, ÇALIŞMA ORTAMINDAKİ RİSKLERİN FARKINDA OLMALI VE GEREKLİ KORUYUCU ÖNLEMLERİ ALMALIDIRLAR

Microleakage under orthodontic brackets bonded with the custom base indirect bonding technique

The gingival sides of group 1 displayed a higher median microleakage score than the occlusal side at the enamel-composite interface but this was not statistically significant (P > 0.05). All occlusal margins in both groups showed no microleakage under orthodontic brackets at the enamel-composite or composite-bracket interfaces. Comparisons of the microleakage scores between the direct and the indirect bonding groups at the enamel-composite and composite-bracket interfaces indicated no statistically significant microleakage differences at the gingival and occlusal margins (P > 0.05). The type of bonding method (direct versus indirect) did not significantly affect the amount of microleakage at the enamel-composite-bracket complex

Bond Strength of Amorphous Calcium Phosphate-Containing Orthodontic Composite Used as a Lingual Retainer Adhesive

Objective: To evaluate the shear bond strength and fracture mode difference between amorphous calcium phosphate (ACP)-containing adhesive and conventional resin-based composite material used as an orthodontic lingual retainer adhesive.AbstractObjective:&nbsp;To evaluate the shear bond strength and fracture mode difference between amorphous calcium phosphate (ACP)&ndash;containing adhesive and conventional resin-based composite material used as an orthodontic lingual retainer adhesive.Materials and Methods:&nbsp;Forty crowns of extracted lower human incisors were mounted in acrylic resin, leaving the buccal surface of the crowns parallel to the base of the molds. The teeth were randomly divided into two groups: experimental and control, containing 20 teeth each. Conventional lingual retainer composite (Transbond-LR, 3M-Unitek) and ACP-containing orthodontic adhesive (Aegis-Ortho) were applied to the teeth surface by packing the material into the cylindrical plastic matrices with a 2.34-mm internal diameter and a 3-mm height (Ultradent) to simulate the lingual retainer bonding. For shear bond testing, the specimens were mounted in a universal testing machine, and an apparatus (Ultradent) attached to a compression load cell was applied to each specimen until failure occurred. The shear bond data were analyzed using Student&#39;s&nbsp;t-test. Fracture modes were analyzed by &chi;2&nbsp;test.Results:&nbsp;The statistical test showed that the bond strengths of group 1 (control Transbond-LR, mean: 24.77 &plusmn; 9.25 MPa) and group 2 (ACP-containing adhesive, mean: 8.49 &plusmn; 2.53 MPa) were significantly different from each other. In general, a greater percentage of the fractures were adhesive at the tooth-composite interface (60% in group 1 and 55% in group 2), and no statistically significant difference was found between groups.Conclusion:&nbsp;The ACP-containing Aegis-Ortho adhesive resulted in a significant decrease in bond strength to the etched enamel surface.Keywords:&nbsp;Bond strength,&nbsp;Amorphous calcium phosphate,&nbsp;Lingual retainer</p

Allergy Skin Tests in Inner-City Children with Allergic Rhinitis Living in İstanbul

Objective: Lifestyle and environmental factors are considered to play an important role in the large variations in the prevalence of symptoms of allergic rhinitis (AR) and allergen sensitization. The aim of the present study was to investigate allergen sensitivities together with clinical features and biochemical characteristics of urban children living in İstanbul. Methods: A total of 2822 patients aged between 2 and 18 years living in Istanbul city center and diagnosed with AR in our allergy polyclinic were included in the study. Results: There were 1095 (38.8%) female and 1727 (61.2%) male patients. The most common susceptibility was to house dust mites, the second was to sweet vernal grass, and the third was to cocksfoot grass. Conclusion: The present study demonstrated that house dust mite is the most common allergen in inner-city children with AR living in Istanbul. Screening house dust mite allergen in inner-city children may be a useful tool in the diagnosis, planning of allergy prevention, and immunotherapy of children suspected with respiratory allergies